Color correction in the compositor from the video editor
If you are already working on the video editor and just want to do color correction, then you can do it with an Adjustment Layer:


Press Shift + A and add Effect Strip > Adjustment Layer.
Press N to bring the Properties panel, scroll to down to the Modifiers and from the Add Strip Modifier drop down menu, you can select whatever you want this strip to do: color balance, curves, etc.


It will affect the strips below, meaning it can affect several strips (several footage clips) at the same time.